[Alneyan]

Yup, Stellar Manipulation. It is dirty cheap in Devnull, as you actually gain money by retrofitting, instead of having to pay extra. A Star Destroyer or two at the border, more if possible, and blast'em as they come within sight. Warp Openers and a riot run are always fun too, or simply Warp Closers: if they cannot reach you, they are dead. Or all of the above. And let's not forget about the Sentry Star Destroyer, with a handful of vessels protecting the wormholes, to take down enemy scouts. Risky, but *fun* if it works.

Of course, they are likely either protected against Stellar Manipulation, or already using the same things themselves. If not... I would go for it. You may be the worst tactician ever (I am), and Stellar Manipulation can still save the day.